How many assessments?

When I compare the trends of assessments as of today with my own schooling years, I find there's a new wave of standard (call it - fancy) assessments. And they are too many... Academic, Application-based, Intelligence tests, Reasoning abilities, plus a plethora of unit tests and weekly assessment...
I am left to wonder how much is too much? Where and when should we draw a line? What are the REAL purposes of an assessment?
Your answers will help...
Thank you,
Rohit